The present invention relates to a liquid detergent composition useful in a wide variety of art fields such as cleaners including a washing detergent for fiber goods, a kitchen detergent, a household detergent and a hard-surface-washing detergent and a liquid cleanser.
The liquid detergent has such an advantage that it is generally superior in water solubility to powdery detergents, it is directly applicable to dirty portions, it needs no drying in production procedures, it can be compounded with thermally instable materials which cannot be incorporated into powdery detergents and it does not require any complicated instrument such as drying facilities.
Incorporation of an alkaline agent, a calcium scavenger, a bleaching agent, an enzyme, an abrasive etc. into the liquid detergent has been desired for supplementary effects. A liquid detergent containing solid components, however, maybe involved easily in problems such that the solid components precipitate and separate in storage, not easily re-dispersed again, and the product will have too high a viscosity to be easily poured into a laundry tank. In order to prevent the solid components from precipitating, increasing the viscosity of the liquid phase or reducing the particle diameter of solid matter has been used. Increasing the viscosity, however, is limited for pouring. It cannot assure a stable dispersion to reduce simply the particle diameter of the solid.
For the purpose of stabilizing a dispersion of solid components, it is known to use a polymeric dispersant to a liquid detergent composition: a copolymer of maleic anhydride and ethylene or vinyl methyl ether hydrolyzed at least at 30% in JP-B 60-39319; a polymer containing an amphiphatic carboxy group in JP-A 3-86800; a copolymer comprising a monomer containing a group being capable of extending from the surface of the solid phase and a monomer containing a group being capable of associating with the solid phase in JP-A 5-140599; and a polymer comprising a monomer showing self-association in the liquid phase and a monomer being soluble in the liquid phase in JP-A 7-508781. However, the solid components used in those reference compositions are stabilized with polymer network, but not satisfactory in dispersion stability.
The purpose of the present invention is to provide a liquid detergent composition being excellent in detergency and dispersion stability.
The inventors have found that the detergency is increased with a polymeric dispersant having a large cation exchanging capacity, that is, having a high calcium-capturing ability and an excellent stability is obtained with a polymeric dispersant having a good affinity with both liquid phase and solid phase.
When the water content of a detergent composition is 5 wt. % or less, a crystalline silicate compound works as an excellent alkaline agent and calcium-capturing agent. Therefore it has been found that an increased detergency and an excellent stability can be obtained with a polymeric dispersant having a good affinity with both liquid phase and solid phase.
The invention provides a liquid detergent composition, having a degree of separation by volume of 5% or less after 1 month of storage at 25xc2x0 C., comprising a liquid phase as the phase (a), a polymeric dispersant as the component (b) and at least one selected from the group consisting of a crystalline silicate compound and an aluminosilicate compound as the component (c), wherein the component (b) has a cation exchange capacity of not less than 120 CaCO3 mg/g when the water content of the composition is 5% by weight or less and then the aluminosilicate compound only is used as the component (c) or when the water content of the composition is larger than 5% by weight.
It is preferable that the content of the phase (a) is 30 to 95% by weight of the composition; the phase (a) comprises 10 to 100% by weight of a surfactant; the content of the component (b) is 0.1 to 10% by weight of the composition; the content of the component (c) is 3 to 69.9% by weight of the composition; the component (b) is a polymer consisting of 2 or more kinds of polymer chains; the component (b) is a block or graft polymer consisting of a polymer chain 1 being soluble or uniformly dispersible in the phase (a) and a polymer chain 2 having a functional group having a good affinity with the component (c); or the component (c) is the crystalline silicate compound.
The invention provides a process for producing the liquid detergent composition as defined above, which comprises a step of wet grinding the components (b) and (c) in the phase (a) to obtain a slurry of finely pulverized solid components.
The process may preferably comprise steps of wet grinding the component (c) in the phase (a) to obtain a slurry of finely pulverized solid component and adding the component (b) to the slurry. It is preferable in the process that the total volume of the phase (a), the component (c) and other solid components is 0.9 to 1.1 times as much as the volume of gaps of media introduced into a media mill at the step of the wet grinding.
Phase (a): Liquid Phase
The content of the phase (a) as the liquid phase of the liquid detergent composition is preferably 30 to 95% by weight, more preferably 40 to 90% by weight. The content of the phase (a) can be determined by sedimenting the solid of the liquid detergent composition (separating conditions: 10,000 rpm, 30 minutes, 25xc2x0 C.) with a centrifuge, himac CR22F (tradename) produced by Hitachi, Ltd., and then quantifying the filtrate from which the sedimented components have been removed through a 0.1 xcexcm membrane filter at 25xc2x0 C., made of PTFE, produced by ADVANTEC Co., Ltd.
The phase (a) comprises a surfactant as an essential ingredient and if necessary water and a water-soluble organic solvent. The phase (a) may contain water. In order to compact the detergent composition, however, the content of water of the phase (a) may be preferably 60% by weight or less and the phase (a) may be more preferably a non-aqueous liquid phase not containing water substantially. The non-aqueous liquid system means that water is not intentionally added and further the content of water of the liquid detergent composition is preferably 5% by weight or less, more preferably 2% by weight or less.
The content of the surfactant of the phase (a) is preferably 10 to 100% by weight, more preferably 50 to 100% by weight or particularly preferably 60 to 100% by weight.
The surfactant is preferably a nonionic surfactant. Insofar as the stability of the product is not deteriorated, an anionic surfactant, a cationic surfactant or an amphoteric surfactant may be used with the nonionic surfactant by dissolving it in the phase (a). The phase (a) is also preferably a nonionic surfactant.
a-1: Nonionic Surfactant
A nonionic surfactant is conventionally incorporated for use in a detergent composition and advantageously provides an excellent detergency and stability. The content of the nonionic surfactant in the surfactants is preferably 70 to 100% by weight, more preferably 90 to 100% by weight and particularly preferably 100% by weight.
As the nonionic surfactant, the known nonionic surfactants described in e.g. xe2x80x9c3-1. Collection of Well Known and Customary Techniques (Powder Detergent for Clothing)xe2x80x9d published by the Japanese Patent Office can be used.
In the liquid detergent composition of the present invention, it is particularly preferable to use a polyethylene oxide- and/or polypropylene oxide-including nonionic surfactant. It is in particular at least one selected from a polyoxyethylene alkyl ether comprising 5 to 20 moles on the average of ethylene oxide added to a C8-18 linear or branched, primary or secondary alcohol and a polyoxyethylene polyoxypropylene alkyl ether comprising 5 to 15 moles on the average of ethylene oxide and 1 to 5 moles on the average of propylene oxide added thereto, the ethylene oxide and propylene oxide having been added in random or in block.
As other nonionic surfactants, it is also possible to use polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl amines, sucrose fatty esters, fatty acid glycerol monoesters, higher fatty acid alkanol amides, polyoxyethylene higher fatty acid alkanol amides, amine oxides, alkyl glycosides, alkyl glyceryl ethers and N-alkyl gluconamides.
a-2: Anionic Surfactant
The known anionic surfactants described in e.g. xe2x80x9c3-1. Collection of Well Known and Customary Techniques (Powder Detergent for Clothing)xe2x80x9d published by the Japanese Patent Office can be used in the liquid detergent composition of the present invention. In particular, anionic surfactants such as sulfonates, sulfates, phosphates and carboxylate are preferably incorporated into it.
An example of the anionic surfactant may be preferably at least one selected from alkyl benzene sulfonates, alkyl sulfates, polyoxyethylene alkyl ether sulfates having the average mole number of ethylene oxide added of 0.5 to 6, monoalkyl phosphates and fatty acid salts, having a linear or branched alkyl or alkenyl group containing 8 to 22 carbon atoms on the average.
The counter ion to the anionic surfactant may include sodium, potassium, magnesium, calcium, a cation such as ethanolamine whose amine has been protonated, quaternary ammonium salts and mixtures thereof. The anionic surfactant may be incorporated by adding it in the acid form and separately adding an alkali such as ethanolamine thereto.
a-3: Cationic Surfactant
The known cationic surfactants described in e.g. xe2x80x9c3-1. Collection of Well Known and Customary Techniques (Powder Detergent for Clothing)xe2x80x9d published by the Japanese Patent Office can be used in the liquid detergent composition of the present invention. For example quaternary ammonium salts such as benzalconium may be preferably incorporated.
a-4: Amphoteric Surfactant
The known amphoteric surfactants described in e.g. xe2x80x9c3-1. Collection of Well Known and Customary Techniques (Powder Detergent for Clothing)xe2x80x9d published by the Japanese Patent office can be used in the liquid detergent composition of the present invention. For example alkyl betain-based amphoteric surfactants may be preferably incorporated.
a-5: Water-Soluble Organic Solvent
The water-soluble organic solvent is incorporated into the present liquid detergent composition for the purposes of regulating the viscosity of the product, preventing gelation of the nonionic surfactant and regulating the solubility of the composition in washing water.
Examples of such water-soluble organic solvents may include polyhydric alcohols such as butanediol, pentanediol, hexanediol, glycerol, trimethylol propane and pentaerythritol, mono-, di- or tri-alkyl ethers of polyhydric alcohols, glycols such as ethylene glycol, propylene glycol, polyethylene glycol and polypropylene glycol, monoalkyl ethers of glycols, monoaryl ethers of glycols, monophenyl ethers of glycols, polyethers, alkylamines, fatty amines, aliphatic or aromatic carboxylic acid amides or alkyl esters, lower alkyl esters, ketones, aldehydes, glycerides etc.
These organic solvents may be incorporated singly or as a mixture thereof. For detergency and for compacting the detergent composition, the content thereof in the phase (a) is preferably 0 to 90% by weight, more preferably 0 to 50% by weight and particularly preferably 0 to 40% by weight.
Component (b): Polymeric Dispersant
The polymeric dispersant has an excellent solubility or a uniform dispersibility to the phase (a) and gives a stable dispersibility to the solid component including the component (c).
In order to achieve a good dispersibility or prevent the viscosity from increasing too much, the content of the component (b) as the polymeric dispersant in the liquid detergent composition is preferably 0.1 to 10% by weight, more preferably 0.1 to 5% by weight and particularly preferably 0.1 to 3% by weight.
The component (b) is soluble or uniformly dispersible in the phase (a). This property can be realized by placing 2 g as the dried of the polymer in a 300 ml beaker, pouring 36.8 g of the phase (a) component into it, stirring it at 150 rpm with a Teflon-coated magnet (3 cm) for 5 hours under heating at 50xc2x0 C., cooling it, allowing it to stand for 30 minutes at 25xc2x0 C., and observing no precipitates at the bottom of the beaker.
The component (b) gives the solid including the component (c) a stable dispersibility. The stable dispersibility means that after the liquid detergent composition of the present invention has been produced, the degree of separation by volume after 1 months of storage at 25xc2x0 C. is 5% or less. The degree of separation by volume refers to a ratio of the volume of a transparent liquid phase separated by precipitation of the solid components to the total volume of the composition. It can be specifically measured by the method described below.
The invention provides a liquid detergent composition, having a degree of separation by volume of 5% or less after 1 month of storage at 25xc2x0 C., comprising a liquid phase as the phase (a), a polymeric dispersant as the component (b) and a crystalline silicate compound and/or an aluminosilicate compound as the component (c), wherein the component (b) has a cation exchange capacity of not less than 120 CaCO3 mg/g, preferably not less than 150 CaCO3 mg/g, more preferably not less than 180 CaCO3 mg/g, when the water content of the composition is 5% by weight or less and then the aluminosilicate compound only is used as the component (c) or when the water content of the composition is larger than 5% by weight.
The larger the cation exchanging capacity is, the more increased detergency the detergent has.
A particularly preferable liquid detergent composition has a degree of separation by volume of 5% or less after 1 month of storage at 25xc2x0 C. and comprises a liquid phase as the phase (a), a polymeric dispersant as the component (b) having a cation exchange capacity of not less than 120 CaCO3 mg/g, preferably not less than 150 CaCO3 mg/g and more preferably not less than 180 CaCO3 mg/g, and a crystalline silicate compound and/or an aluminosilicate compound as the component (c). The cation exchanging capacity of the component (b) may be 320 CaCO3 mg/g or less.
As used herein, the cation exchange capacity is a value determined in the following method. About 0.1 g of the component (b) is accurately weighed and dissolved in 100 ml of 0.1 M NH4Clxe2x80x94NH4OH buffer at pH 10. The solution is kept at 25xc2x0 C. and titrated with a calcium ion solution containing 20,000 ppm as CaCO3 at pH 10 while the electric potential is measured. The concentration of calcium ion remaining in the solution is estimated from the relationship between the volume of the dropwise added solution and the potential changes. The amount of captured calcium ion is calculated. The amount of captured calcium ion as determined by this method is expressed in term of cation exchange capacity.
The component (b) is preferably a polymer consisting of two or more kinds of polymer chains, including polymer chains being soluble or uniformly dispersible in the phase (a) described above and polymer chains giving the solid components including the component (c) a stable dispersibility. It is more preferably a block or graft polymer.
It is in particular preferably a polymer having polymer chains being soluble or uniformly dispersible in the phase (a), polymer chains having a functional group having a good affinity with the component (c) and polymer chains consisting mainly of a vinyl monomer having a carboxyl group effectively to capture calcium, preferably having a cation exchange capacity of not less than 120 CaCO3 mg/g as determined by the above method. In the polymer chains, the monomer(s) of one polymer chain may overlap with that of another polymer chain.
As the monomers forming polymer chains being soluble or uniformly dispersible in the phase (a), at least one selected the following monomers (1) to (13) can be used. There is no particular limitation. The monomers (1) and (2) principally produce polymer chains showing a good solubility in the phase (a) of the liquid detergent composition having a water content of larger than 5% by weight of the whole composition, due to a relatively good affinity to water. The monomers (3) to (13) principally produce polymer chains showing a good solubility in the phase (a) of the liquid detergent composition having a water content of 5% by weight or less of the whole composition, due to a relatively good affinity to surfactants and water-soluble organic solvents.
(1) Vinyl monomer having a sulfonic acid group. For example, styrenesulfonic acid or a salt thereof, 2-acrylamide-2-methylpropanesulfonic acid or a salt thereof and (meth)allyl sulfonic acid or a salt thereof are preferable.
(2) Vinyl monomer having a cation group. For example, 2-[(meth)acryloyloxy]ethyl trimethyl ammonium chloride, vinyl benzyl trimethyl ammonium chloride, ethyl sulfate 2-[(meth)acryloyloxy]ethyldimethyl ethyl ammonium, 3-[(meth)acrylamide]propyl trimethyl ammonium chloride, diallyl dimethyl ammonium chloride, etc. are preferable.
(3) Vinyl ether having a C1-22 unsubstituted or substituted, saturated or unsaturated alkyl, aryl or aralkyl group. For example, methyl vinyl ether, ethyl vinyl ether, 4-hydroxybutyl vinyl ether, phenyl vinyl ether, etc. are preferable.
(4) (Meth)acrylamide unsubstituted or substituted on the nitrogen atom thereof with C1-12 saturated or unsaturated alkyl or aralkyl group. For example, (meth)acrylamide, N-methyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-t-butyl(meth)acrylamide, N-(meth)acryloyl morpholine, N-[2-(N,N-dimethylamino)ethyl](meth)acrylamide, N-[3-(N,N-dimethylamino) propyl](meth)acrylamide, N-[2-hydroxyethyl](meth)acrylamide, N-methylol(meth)acrylamide, N-butoxymethyl(meth)acrylamide, etc. are preferable.
(5) N-vinyl fatty amide. For example, N-vinyl pyrrolidone, N-vinyl acetamide, N-vinyl formamide, etc. are preferable.
(6) (Meth)acrylate having C1-22 unsubstituted or substituted, saturated or unsaturated alkyl or aralkyl group. For example, methyl(meth)acrylate, ethyl(meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-(N,N-dimethylamino)ethyl(meth)acrylate, 2-methoxyethyl(meth)acrylate, polyethylene glycol mono(meth)acrylate, etc. are preferable.
(7) Alkylene oxide. For example, ethylene oxide, propylene oxide, etc. are preferable.
(8) Cyclic imino-ether. For example, 2-methyl-2-oxazoline, 2-phenyl-2-oxazoline, etc. are preferable.
(9) Styrene. For example, styrene, 4-ethyl styrene, xcex1-methyl styrene, etc. are preferable.
(10) Vinyl ester. For example, vinyl acetate, vinyl caproate, etc. are preferable.
(11) Polyester consisting of dihydric alcohol and dibasic carboxylic acid. For example, a polycondensate product of polyethylene glycol and terephthalic acid or 1,4-butanediol and succinic acid, etc. are preferable.
(12) Polyamide. For example, a ring-opening polymerization product of N-methyl valerolactam is preferable.
(13) Polyurethane. For example, a polyaddition product of polyethylene glycol, hexamethylene diisocyanate and N-methyl-diethanolamine or 1,4-butanediol, etc. are preferable.
The constituting units of the above shown monomers may be contained in the polymer chains in an amount of 60 mole percent or more in order to have a solubility or a uniform dispersibility in the phase (a), preferably 80 mole percent or more, more preferably 90 mole percent or more, the most preferably 100 mole percent. A monomer being copolymerizable with them may be added.
The functional group having a good affinity with the component (c) may include carboxyl group, sulfonic acid group, phosphoric acid group, hydroxy group, primary to tertiary amino groups, quaternary ammonium group etc. As the monomers forming polymer chains having a good affinity-having (lipophilic) group with the component (c), it is possible to use one or more members selected from (meth)acrylic acid and salts thereof, styrene carboxylic acid and salts thereof, maleic acid and salts thereof, itaconic acid and salts thereof, styrenesulfonic acid and salts thereof, (meth)allyl sulfonic acid and salts thereof, 2-acrylamide-2-methylpropanesulfonic acid and salts thereof, vinyl sulfonic acid and salts thereof, vinyl alcohol, 2-hydroxyethyl(meth)acrylate, N-[2-hydroxyethyl](meth)acrylamide, 4-hydroxymethyl styrene, mono-2-[(meth)acryloyloxy]ethyl phosphate, 2-[(meth)acryloyloxy]ethyl trimethyl ammonium chloride, vinyl benzyl trimethyl ammonium chloride, 2-[(meth)acryloyloxy]ethyl dimethyl ethyl ammonium ethyl sulfate, 3-[(meth)acrylamide]propyl trimethyl ammonium chloride, diallyl dimethyl ammonium chloride, vinyl pyridine, etc.
The constituting units of the above shown monomers may be contained in the polymer chains in an amount of 60 mole percent or more in order to have a good affinity with the phase (c), preferably 80 mole percent or more, more preferably 90 mole percent or more, the most preferably 100 mole percent. A monomer being copolymerizable with them may be added.
The monomers forming polymer chains consisting mainly of a vinyl monomer having a carboxyl group effectively to capture calcium, include (meth)acrylic acid and salts thereof, styrene carboxylic acid and salts thereof, maleic acid and salts thereof, and itaconic acid and salts thereof. One or more members selected from these monomers can be used.
The constituting units of the above shown monomers may be contained in the polymer chains in an amount of 60 mole percent or more in order to capture calcium very well, preferably 80 mole percent or more, more preferably 90 mole percent or more, the most preferably 100 mole percent. A monomer being copolymerizable with them may be added.
These polymer chains consisting mainly of a vinyl monomer having a carboxyl group also have a high affinity with the component (c) and the component (b) including these polymer chains no longer needs any other polymer chains having a high affinity with the component (c).
The component (b) is more preferably a block or graft polymer comprising a polymer chain being soluble or uniformly dispersible in the phase (a) (referred to hereinafter as polymer chain 1) and a polymer chain having a functional group with a high affinity to the component (c) (referred to hereinafter as polymer chain 2). In a particularly preferable component (b), the polymer chain with a high affinity to the component (c) is a polymer chain derived from a vinyl monomer having a carboxyl group.
By the presence of the two polymer chains, performances of both are effectively achieved. To demonstrate effective performances of both, the polymer is particularly preferably a graft polymer. The proportion of the two polymer chains by weight, that is, (polymer chain 1)/(polymer chain 2), is preferably from 5/95 to 95/5. The method of synthesizing such block or graft polymer is not particularly limited and a known method can be selected. In particular, a method of polymerizing a vinyl monomer etc. by means of a macro-azo initiator having an azo group in the polymer chain thereof (macro-azo initiation method), a method of using a compound having a polymerizable group at one end of the polymer chain thereof (macro-monomer method), a method of linking a newly formed polymer chain by chain transfer reaction to a previously coexistent polymer chain (chain transfer method), and a method of linking the terminal of one polymer chain through reaction to a functional group in the other polymer chain are preferable.
Preferable examples of the component (b) obtained in these methods include the followings 1 to 12:
1. A block polymer obtained by radical polymerization of (meth)acrylic acid (or a salt thereof) by use of a polyethylene glycol macro-azo initiator.
2. A copolymer of polyethylene glycol mono(meth)acrylate and (meth)acrylic acid (or a salt thereof).
3. A copolymer of polyethylene glycol mono(meth)acrylate and styrenesulfonic acid (or a salt thereof).
4. A copolymer of polyethylene glycol mono(meth)acrylate and 2-((meth)acryloyloxy)ethyltrimethyl ammonium chloride.
5. A copolymer of polyethylene glycol mono(meth)acrylate and 2-hydroxyethyl(meth)acrylate.
6. A graft polymer obtained by radical polymerization of acrylic acid and maleic acid (or a salt thereof) in polyethylene glycol, polypropylene glycol or polyethylene glycol-propylene glycol.
7. A graft polymer obtained by radical polymerization of diallyl dimethyl ammonium chloride in an aqueous solution of poly(N,N-dimethyl acrylamide/styrene) copolymer.
8. A graft polymer obtained by radical polymerization of 2-acrylamide-2-methyl-propanesulfonic acid (or a salt thereof) in an aqueous solution of poly(N,N-dimethyl(meth)acrylamide).
9. A graft polymer obtained by linking poly(meth)acrylic acid through dehydration reaction to polyethylene glycol having hydroxyl group at the terminal thereof.
10. A graft polymer obtained by radical polymerization of acrylic acid and maleic acid (or a salt thereof) in an aqueous solution of polystyrene sulfonate.
11. A graft polymer obtained by radical polymerization of diallyl dimethyl ammonium chloride in an aqueous solution of poly(acrylic acid/maleic acid).
12. A graft polymer obtained by radical polymerization of polyethylene glycol allyl ether and maleic acid.
In the above shown (co)polymers 1 to 12, those having the polyethylene glycol units may have an alkoxy group such as methoxy.
Particularly preferable polymers among those described above are polymers 1, 2, 6, 9 and 12.
When the content of water of the liquid detergent composition of the present invention is 5% by weight or less, the polymers 2, 6, 12, 9, 1 and other polymers are increasingly less preferable in this order. The polymer 2 is the most important. These polymers have a relatively high solubility and/or uniform dispersibility in the liquid phase in the case of 5 wt. % or less of water.
When the content of water therein is larger than 5% by weight, the polymers 10, 6, 2, 12, 9 and other polymers are increasingly less preferable in this order. 10 is the most preferable. These polymers have a relatively high solubility and/or uniform dispersibility in the liquid phase in the case of larger than 5 wt. % of water.
The polymers 2, 6, 12 and 9 have a good affinity to both liquid phases.
The salt of the component (b) preferably includes a basic amino acid salt, an alkali metal salt such as sodium salt and potassium salt, an ammonium salt and an alkanol ammonium salt having the total carbon number of 1 to 12. The alkali metal salt is more preferable. The sodium salt is much more preferable.
For preventing too much an increase in the viscosity, the weight average molecular weight of the component (b) is preferably 1,000,000 or less, more preferably 1000 to 500,000, particularly preferably 5000 to 300,000.
Component (c): Crystalline Silicate Compound and/or Aluminosilicate Compound
The component (c) is at least one member selected from a crystalline silicate compound and an aluminosilicate compound, and the total content thereof in the liquid detergent composition is preferably 3 to 69.9% by weight, more preferably 10 to 60% by weight.
The crystalline silicate compound includes those compounds represented by formula (I):
(M1pM2qM3rO)(M4sM5tO)x(SiO2)yxe2x80x83xe2x80x83(I) 
wherein M1, M2 and M3 represent Na, K or H; M4 and M5 each represent Ca or Mg; p, q and r each represent a number of 0 to 2, provided that p+q+r=2; s and t each represent a number of 0 to 1, provided that s+t=1; x is a number of 0 to 1; and y is a number of 0.9 to 3.5.
Specifically, the crystalline silicate compound includes layered sodium silicate, for example SKS-6 (Hoechst) and those described in claims in Japanese Patent No. 2525318, Japanese Patent No. 2759243, Japanese Patent No. 2618799, Japanese Patent No. 2525342, and JP-A 5-184946.
Further, the aluminosilicate compound includes those compounds represented by formula (II):
(M1pM2qM3rO)u(M4sM5tO)v(Al2O3)w(SiO2)xe2x80x83xe2x80x83(II) 
wherein M1, M2, M3, M4, M5, p, q, r, s and t have the same meanings as defined above; u is a number of 0 to 1, preferably 0.1 to 0.5; v is a number of 0 to 1, preferably 0 to 0.1; and w is a number of 0 to 0.6, preferably 0.1 to 0.5.
Such aluminosilicate compounds include e.g. various zeolites of types A, X and P, used conventionally in detergents, and in particular type A is preferable. A zeolite has a high cation exchange ability and is thus a very excellent builder for detergent, and the incorporation thereof is preferable because the detergency of the resulting detergent composition is significantly improved. Such zeolites include Toyo Builder (tradename) commercially available from Tosoh Corporation. Further, fine zeolites produced by the method described in JP-A 11-318604 are also preferably used because in the process for producing the present detergent composition as described below they are easily finely ground whereby the dispersion stability of the composition is improved. Generally, commercial zeolites contain about 20% water. For production of the liquid detergent composition not substantially containing water, it is preferable that such commercial zeolites are used after water has been removed by calcination at 450 to 600xc2x0 C.
The average particle diameter of the component (c) is 500 xcexcm or less, preferably 0.1 to 20 xcexcm, more preferably 0.1 to 2 xcexcm, and particularly preferably 0.1 to 1.0 xcexcm. Unless otherwise specified, the average particle diameter refers to an average particle diameter on volume basis as determined by a laser scattering particle size distribution analyzer, LA-910 manufactured by Horiba, Ltd.
Other Components (d)
The liquid detergent composition of the present invention can further comprise, as other components, a surfactant being insoluble in the phase (a), an inorganic builder, an organic builder, a bleaching agent and other conventional additives to detergent.
If these components are solids, these components similar to the component (c) can be finely pulverized, dispersed, and incorporated into the present detergent composition in the method described below. In this case, the average particle diameter of each solid component is preferably 500 xcexcm or less, preferably 0.1 to 20 xcexcm, more preferably 0.1 to 2 xcexcm, and particularly preferably 0.1 to 1.0 xcexcm.
d-1: Surfactant Insoluble in the Phase (a)
The liquid detergent composition of the present invention comprises a surfactant in the phase (a), and then separately another surfactant being insoluble in the phase (a) may be dispersed and incorporated as a solid component.
d-2: Inorganic Builder
Besides the component (c), known washing builders such as silicates, metasilicates and carbonates can be arbitrarily compounded. These are preferably alkaline metal salts.
For example, phosphates such as tripolyphosphates and pyrophosphates, aminotri(methylene phosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylene diamine tetra(methylene phosphonic acid), diethylene triamine penta(methylene phosphonic acid) or salts thereof can also be used.
d-3: Organic Builder
The liquid detergent composition of the present invention can also comprise known organic builders being soluble or insoluble in the phase (a). Examples of such organic builders include polybasic carboxylic acids such as citric acid, succinic acid and malonic acid, amino acids such as aspartic acid and glutamic acid, amino polyacetic acids such as nitrilo triacetic acid and ethylene diamine tetraacetic acid, and polymeric polybasic carboxylic acids such as polyacrylic acid, acrylic acid/maleic acid copolymers etc. These are preferably in the form of salts such as alkaline metal salts, ammonium salts and substituted ammonium salts.
d-4: Bleaching Agent
Further, the liquid detergent composition of the present invention preferably comprises a bleating agent. As the bleaching agent, an inorganic peroxide bleaching, or an inorganic peroxide bleaching agent combined with a bleach-activating agent, can be used.
Examples of the inorganic peroxide bleaching agent are alkali metal perborates, percarbonates, persilicates and perphosphates, particularly preferably sodium perborate, sodium percarbonate etc. For improving the dispersion stability of the product, percarbonates coated with carboxylic acid type polymers and/or polycarboxylic acids mentioned in lines 13 to 44 in column 2 on page 2 in JP-A 11-279593 can be used.
If the inorganic peroxide bleaching agent is used in combination with a bleach-activating agent, the bleach-activating agent is usually an organic compound having one or more reactive acyl groups forming peracid, by which the bleaching action is rendered more effective than by using the inorganic peroxide bleaching agent singly. Although the structure of the bleach-activating agent is not particularly limited, it is preferably the one shown in formula (III): 
wherein R1 represents a C1-15 linear or branched alkyl group and X represents COOM or SO3M, M being a hydrogen atom, an alkali metal atom or an alkaline earth metal atom.
In the bleach-activating agent represented by formula (III), it is preferable that R1 is a C7-11 linear or branched alkyl group and X is COOH or SO3Na. Such bleach-activating agents include sodium lauroyloxybenzene sulfonate, sodium decanoyloxybenzene sulfonate, sodium octanoyloxybenzene sulfonate, lauroyloxybenzoic acid, decanoyloxybenzoic acid, octanoyloxybenzoic acid etc.
Other conventionally used detergent additives, for example, polymers such as polyethylene glycol and carboxymethyl cellulose, color migration-preventing agents such as polyvinyl pyrrolidone, enzymes such as protease, cellulase and lipase, enzyme stabilizers such as calcium chloride, formic acid and boric acid, defoaming agents such as silicone, antioxidants such as butyl hydroxy toluene, distyranated cresol, sodium sulfite and sodium hydrogen sulfite, perfumes, dyes, fluorescent dyes, pigments etc. may be contained as necessary.
The liquid detergent composition of the present invention can be produced by process 1, preferably consisting of steps 1, 2 and 3, including the step of wet grinding the components (b) and (c) in the phase (a) to prepare a slurry of finely pulverized solid components, or by process 2, preferably consisting of steps 1, 2, 3 and 4, including the step of wet grinding the component (c) in the phase (a) to prepare a slurry of finely pulverized solid component, followed by adding the component (b)
In step 1, the surfactant as the phase (a) and as necessary a water-soluble organic solvent and deionized water are mixed and the component (b) is dissolved or uniformly dispersed therein (referred to hereinafter as dispersion medium (1)). In this step, the mixture can also be heated at a suitable temperature, for example at 50 to 60xc2x0 C. A bleach-activating agent, a peroxide-type bleacher component, an enzyme, a brightening agent, a perfume etc. are added preferably in step 3 described below.
In step 2, the component (c) and a mixture of other solid components to be ground are wet ground in the dispersion medium (1). The component (c), upon being finely pulverized, increases the surface area thereof to increase the rate of calcium exchange, thus acting as a further excellent washing builder. It is however known that the component (c) is then liable to gradual chemical change attributable to vapor and carbon dioxide in air to deteriorate the calcium exchange ability, and this phenomenon is enhanced by an increase in the surface area, thus making it difficult to incorporate the finely pulverized crystalline silicate compound or aluminosilicate compound into a powdery detergent etc. Japanese Patent No. 2958506 discloses a process for producing a particulate solid builder, which comprises wet grinding a solid builder such as a crystalline silicate compound and an aluminosilicate compound in a dispersion medium containing a surfactant, according to which, finely pulverized, excellent crystalline silicate and aluminosilicate compounds having a high calcium exchange ability can be obtained.
Preferable examples of the surfactant, the water-soluble organic solvent and the solid builder, such as inorganic and organic builders other than the crystalline silicate compound and aluminosilicate compound of the present liquid detergent composition are those described above. Solid components other than the solid builder in the present composition are also be finely pulverized in an analogous manner. When liquid phase-insoluble bleach-activating agent, other than the solid builder, is incorporated, it may be wet grouond together with the other solid components, added in the wet grinding step or incorporated in step 3.
The means of wet grinding includes a stone mill, a colloid mill, a KD mill, a slasher mill, a high-speed disperser, a media mill, a roll mill, a kneader, an extruder, a grinder with a liquid jet interaction chamber (e.g., a micro-flydizer manufactured by Microflydex Co., Ltd.), an ultrasonic dispersing instrument etc., and in particular, wet grinding using media, for example a method of using a sand mill, a sand grinder, a wet vibration mill, an attritor etc. is preferable in respect of the efficiency of grinding. As the media, known materials such as titania and zirconia can be used.
The media having a diameter of 0.1 to 1.0 mm are particularly suitable for grinding with a sand mill. When the particle size of the solid builder as a starting material is particularly large, the solid builder may be ground effectively by previously dry-grinding it until the particle size is reduced to a suitable size for wet grinding, for example 2 to 300 xcexcm, or by grinding it by media having a larger diameter, for example a diameter of 2 mm and then grinding it by media with a smaller diameter.
To improve the efficiency of wet grinding the solid components, grinding is conducted preferably such that the ratio by weight of [the component (c) and a mixture with other solid components (or approximately the component (c)]/[the dispersion medium (1) (or approximately the component (a)] is from 30/70 to 60/40.
To improve the efficiency of wet grinding the solid components, the total volume of [the component (c) and a mixture with other solid components (or approximately the component (c)] and [the dispersion medium (1) (or approximately the component (a)] is preferably 0.9 to 1.1 times, more preferably 0.95 to 1.05 times as much as the volume of gaps of media introduced into a media mill such as sand mill, sand grinder, wet vibration mill and attritor. The term, the volume of 1.0 time as much as the volume of gaps of media refers to the volume of deionized water which has been introduced quietly at 20xc2x0 C. into media until it reached the top of the media packed densely under vibration in advance.
Wet grinding is continued preferably 3 minutes or more, more preferably 5 minutes or more, until the average particle diameter of the solid components does not change.
To keep the viscosity low in the system and to improve the efficiency of grinding, the component(s) of the phase (a) can be added in divided portions. The component(s) of the phase (a) added in this step may be different from those of the step 1. Depending on the volume of the component added, the media are also added preferably so as to maintain the above shown ratio of the total volume to the volume of gaps of the media.
The average particle diameter of the resulting slurry of the finely pulverized solid components is preferably 500 xcexcm or less, preferably 0.1 to 20 xcexcm, more preferably 0.1 to 2 xcexcm, and particularly preferably 0.1 to 1.0 xcexcm.
Depending on the case, components of the phase (a) may be further added so as to attain a desired compounding ratio. After they have been mixed, the media may be removed, or after the other components have been added in step 3, the media may be removed.
In step 3, solid components preferably, not subjected to wet grinding in step 2, and other arbitrary components being soluble in the liquid are mixed and compounded therewith. The particle size of the solid components, preferably not subjected to wet grinding instep 2, may previously have been reduced under gentle conditions.
In step 1, a surfactant and as necessary a water-soluble organic solvent and deionized water are mixed to form the phase (a). A bleach-activating agent, a peroxide type bleacher component, an enzyme, a brightening agent, a perfume etc. are added preferably in step 4 described later.
In step 2, the component (c) and a mixture of other solid components to be ground are wet ground in the phase (a) The component (c), upon being finely pulverized, increases the surface area thereof to increase the rate of calcium exchange, thus acting as a further excellent washing builder. It is however known that the component (c) is then liable to gradual chemical change attributable to vapor and carbon dioxide in air to deteriorate the calcium exchange ability, and this phenomenon is enhanced by an increase in the surface area, thus making it difficult to incorporate the finely pulverized crystalline silicate compound or aluminosilicate compound into a powdery detergent etc. Japanese Patent No. 2958506 discloses a process for producing a particulate solid builder which comprises wet grinding a solid builder such as a crystalline silicate compound and an aluminosilicate compound in a dispersion medium containing a surfactant, and according to this process, finely pulverized, excellent crystalline silicate and aluminosilicate compounds having a high calcium exchange ability can be obtained. Preferable examples of the surfactant, the water-soluble organic solvent and the solid builder (e.g. inorganic and organic builders besides the crystalline silicate compound and aluminosilicate compound) in the present liquid detergent composition are those described above, and solid components other than the solid builder in the present composition are also be finely pulverized in an analogous manner. When the liquid phase-insoluble bleach-activating agent among the solid components other than the solid builder is compounded, it may be wet ground together with the other solid components, may be added and ground during wet grinding, or may be compounded in step 4.
As the wet grinding, wet grinding particularly using media, for example, a method of using a sand mill, a sand grinder, a wet vibration mill, an attritor etc. is suitable for the efficiency of grinding. As the media, known materials such as titania and zirconia can be used.
The media having a diameter of 0.1 to 1.0 mm are particularly suitable for grinding with a sand mill. When the particle size of the solid builder as a starting material is particularly large, the solid builder may be ground effectively by previously dry-grinding it until the particle size is reduced to a suitable size for wet grinding, for example 80 to 300 xcexcm, or by grinding it by media having a larger diameter, for example a diameter of 2 mm and then grinding it by media with a smaller diameter.
To improve the efficiency of wet grinding the solid components, the total volume of [the component (a), the component (c), and a mixture with other solid components (or approximately the component (c) only)] is preferably 0.9- to 1.1 times, more preferably 0.95- to 1.05 times as much as the volume of gaps of media introduced into a media mill (sand mill, sand grinder, wet vibration mill, attritor etc.). The term the volume of 1.0 time as much as the volume of gaps of media refers to the volume of deionized water which has been introduced quietly at 20xc2x0 C. into media until it reached the top of the media packed in advance densely under vibration.
To improve the efficiency of wet grinding the solid components, grinding is conducted preferably such that the ratio by weight of [the component (c) and a mixture with other solid components (or approximately the component (c)]/[the phase (a)] is from 30/70 to 60/40.
Wet grinding is continued preferably 3 minutes or more, more preferably 5 minutes or more, until the average particle diameter of the solid components does not change.
To keep the viscosity low in the system and to improve the efficiency of grinding, the component in the phase (a) can be added in divided portions. The component in the phase (a) added in this step may be different from the component in the dispersion medium obtained in step 1. Depending on the volume of the component added, the media are also added preferably so as to keep the ratio of the above total volume to the volume of the gaps of the media.
The average particle diameter of the resulting slurry of the finely pulverized solid components is preferably 500 xcexcm or less, preferably 0.1 to 20 xcexcm, more preferably 0.1 to 2 xcexcm, and particularly preferably 0.1 to 1.0 xcexcm.
In step 3, the component (b) is dissolved or uniformly dispersed in the phase (a) in another tank to which a surfactant and as necessary a water-soluble organic solvent and deionized water were added. The component in the phase (a) used in this step may be different from the component in the dispersion medium in step 1.
The phase (a) containing the component (b) is added to and mixed with the slurry of the finely divided solid components obtained in step 2. At the time of compounding the component (b), the mixture can also be heated at a suitable temperature, for example 50 to 60xc2x0 C. Thereafter, a part of the phase (a) maybe further added so as to attain a desired compounding ratio. After they are mixed, the media may be removed, or after the other components are added and mixed in step 4, the media may be removed.
In step 4, solid components preferably not subjected to wet grinding in step 2 and other arbitrary components soluble in the liquid are mixed and compounded therewith. The particle size of the solid components preferably not subjected to wet grinding in step 2 may previously have been reduced under gentle conditions.
The liquid detergent composition of the present invention can be produced in either process 1 or 2, but process 2 is more preferable because the component (c) can be easily finely pulverized and better stability can be achieved.
Further, when solid components previously sufficiently pulverized by dry-grinding etc. are used, a dispersing instrument such as a flow jet mixer or the like can be used to easily prepare the liquid detergent composition.
For improving the dispersion stability of particles and preventing scattering of the liquid during use, the viscosity of the present liquid detergent composition is preferably about 10 to 5000 mPa.s, more preferably 100 to 3000 mPa.s. The viscosity was determined at 25xc2x0 C. by measuring 200 g of this composition in 200 ml beaker by No. 2 rotor under the rate condition of 30 rpm in a Brookfield type viscometer manufactured by Tokyo Keiki Co., Ltd.
The liquid detergent composition of the present invention comprises fine solid particles including those of a crystalline silicate compound and/or an aluminosilicate compound dispersed stably by a polymeric dispersant in a surfactant-containing liquid without increasing the viscosity of the product, and can be easily introduced into a laundering tank and rapidly dissolved in washing water. Further, the polymeric dispersant having a high cation exchange ability can act as a builder in washing water, to compact the detergent composition and to exhibit excellent detergency.